Methods for fabricating group III nitride compound semiconductors and group III nitride compound semiconductor devices

Abstract

The present invention provides a Group III nitride compound semiconductor with suppressed generation of threading dislocations. A GaN layer 31 is subjected to etching, so as to form an island-like structure having a shape of, for example, dot, strip, or grid, thereby providing a trench / mesa structure, and a mask 4 is formed at the bottom of the trench such that the upper surface of the mask 4 is positioned below the top surface of the GaN layer 31. A GaN layer 32 is lateral-epitaxially grown with the top surface 31a of the mesa and sidewalls 31b of the trench serving as nuclei, to thereby bury the trench, and then epitaxial growth is effected in the vertical direction. In the upper region of the GaN layer 32 formed above the mask 4 through lateral epitaxial growth, propagation of threading dislocations contained in the GaN layer is 31 can be prevented.

Description

TECHNICAL FIELD

[0002] The present invention relates to a method for fabricating Group III nitride compound semiconductors. More particularly, the present invention relates to a method for fabricating Group III nitride compound semiconductors employing epitaxial lateral overgrowth (ELO). The Group III nitride compound semiconductors are generally represented by AlxGayIn1-x-yN (wherein 0≦x≦1, 0≦y≦1, and 0≦x+y≦1), and examples thereof include binary semiconductors such as AlN, GaN, and InN; ternary semiconductors such as AlxGa1-xN, AlxIn1-xN, and GaxIn1-xN (wherein 0<x<1); and quaternary semiconductors such as AlxGayIn1-x-yN (wherein 0<x<1, 0<y<1, and 0<x+y<1). In the present specification, unless otherwise specified, “Group III nitride compound semiconductors” encompass Group III nitride compound semiconductors which are doped with an impurity so as to assume p-type or n-type conductivity.BACKGROUND ART

[0003] Group III nitride compound semiconductor are direct-tr...

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